Chlorinated aromatic compounds are useful intermediates for the production of many pesticides, pharmaceuticals, and dyes. However, the yield and the selectivity of chlorination obtained from the existing aromatic compound-chlorinating reactions are poor. As chemical intermediates, most aromatic compounds have complex chemical structures, and factors such as spatial effects and inert substituents lead to harsh reaction conditions, low yield, and poor selectivity of chlorination.
Two methods are predominately used for the chlorination of aromatic compounds. The first method utilizes Lewis acids and sulfur compounds as catalysts. This method can improve the selectivity of chlorination of aromatic rings, but the difficult synthesis and identification of sulfur compounds limits the practical application of this method. The second method uses zeolite sieve catalysis technology, which enhances the yield and selectively of some chlorination reactions, yet some aromatic compounds cannot be chlorinated using the method.